The legacy`monkeyrunner`tool provides an API for writing programs that control an Android device or emulator from outside of Android code.

The`monkeyrunner`tool is primarily designed to test apps and devices at the functional/framework level and for running unit test suites, but you can use it for other purposes. With`monkeyrunner`, you can write a Python program that installs an Android app or test package, runs it, sends keystrokes to it, takes screenshots of its user interface, and stores screenshots on the workstation.

**Caution:** The`monkeyrunner`API is unmaintained. We recommend using the[App Crawler](https://developer.android.com/studio/test/other-testing-tools/app-crawler)tool or[UI Automator](https://developer.android.com/training/testing/other-components/ui-automator)testing framework instead.

The`monkeyrunner`tool isn't related to the[UI/Application Exerciser Monkey](https://developer.android.com/tools/help/monkey), also known as the`monkey`tool. The`monkey`tool runs in an[adb](https://developer.android.com/tools/help/adb)shell directly on the device or emulator and generates pseudo-random streams of user and system events. In comparison, the`monkeyrunner`tool controls devices and emulators from a workstation by sending specific commands and events from an API.

The`monkeyrunner`tool provides these features for Android testing:

- **Multiple device control** : The`monkeyrunner`API can apply one or more test suites across multiple devices or emulators. You can physically attach all the devices or start up all the emulators (or both) at once, connect to each one in turn programmatically, and then run one or more tests. You can also start up an emulator configuration programmatically, run one or more tests, and then shut down the emulator.
- **Functional testing** :`monkeyrunner`can run an automated start-to-finish test of an Android app. You provide input values with keystrokes or touch events and view the results as screenshots.
- **Regression testing** :`monkeyrunner`can test app stability by running an app and comparing its output screenshots to a set of screenshots that are known to be correct.
- **Extensible automation** : Since`monkeyrunner`is an API toolkit, you can develop a system of Python-based modules and programs for controlling Android devices. Besides using the`monkeyrunner`API itself, you can use the standard Python[os](http://docs.python.org/library/os.html)and[subprocess](http://docs.python.org/library/subprocess.html)modules to call Android tools, such as[Android Debug Bridge](https://developer.android.com/tools/help/adb).

  You can also add your own classes to the`monkeyrunner`API. This is described in more detail in the[Extend monkeyrunner with plugins](https://developer.android.com/studio/test/monkeyrunner#Plugins)section.

The`monkeyrunner`tool uses[Jython](http://www.jython.org/), an implementation of Python that uses the Java programming language. Jython lets the`monkeyrunner`API interact easily with the Android framework. With Jython, you can use Python syntax to access the constants, classes, and methods of the API.

## A simple monkeyrunner program

Here is a simple`monkeyrunner`program that connects to a device, creating a[MonkeyDevice](https://developer.android.com/tools/help/MonkeyDevice)object. Using the`MonkeyDevice`object, the program installs an Android application package, runs one of its activities, and sends key events to the activity. The program then takes a screenshot of the result, creating a[MonkeyImage](https://developer.android.com/tools/help/MonkeyImage)object. From this object, the program writes out a PNG file containing the screenshot.  

```python
# Imports the monkeyrunner modules used by this program.
from com.android.monkeyrunner import MonkeyRunner, MonkeyDevice

# Connects to the current device, returning a MonkeyDevice object.
device = MonkeyRunner.waitForConnection()

# Installs the Android package. Notice that this method returns a boolean, so you can test
# whether the installation worked.
device.installPackage('myproject/bin/MyApplication.apk')

# Sets a variable with the package's internal name.
package = 'com.example.android.myapplication'

# Sets a variable with the name of an Activity in the package.
activity = 'com.example.android.myapplication.MainActivity'

# Sets the name of the component to start.
runComponent = package + '/' + activity

# Runs the component.
device.startActivity(component=runComponent)

# Presses the Menu button.
device.press('KEYCODE_MENU', MonkeyDevice.DOWN_AND_UP)

# Takes a screenshot.
result = device.takeSnapshot()

# Writes the screenshot to a file.
result.writeToFile('myproject/shot1.png','png')
```

## The monkeyrunner API

The`monkeyrunner`API is contained in three modules in the`com.android.monkeyrunner`package:

- [MonkeyRunner](https://developer.android.com/tools/help/MonkeyRunner): A class of utility methods for`monkeyrunner`programs. This class provides a method for connecting`monkeyrunner`to a device or emulator. It also provides methods for creating UIs for a`monkeyrunner`program and for displaying the built-in help.
- [MonkeyDevice](https://developer.android.com/tools/help/MonkeyDevice): Represents a device or emulator. This class provides methods for installing and uninstalling packages, starting an Activity, and sending keyboard or touch events to an app. You also use this class to run test packages.
- [MonkeyImage](https://developer.android.com/tools/help/MonkeyImage): Represents a screen capture image. This class provides methods for capturing screens, converting bitmap images to various formats, comparing two`MonkeyImage`objects, and writing an image to a file.

In a Python program, you access each class as a Python module. The`monkeyrunner`tool does not import these modules automatically. To import a module, use the Python`from`statement:  

```python
from com.android.monkeyrunner import <module>
```

Where`<module>`is the class name you want to import. You can import more than one module in the same`from`statement by separating the module names with commas.

## Run monkeyrunner

You can run`monkeyrunner`programs either from a file or by entering`monkeyrunner`statements in an interactive session. You do both by invoking the`monkeyrunner`command, which is found in the`tools/`subdirectory of your SDK directory. If you provide a filename as an argument, the`monkeyrunner`command runs the file's contents as a Python program; otherwise, it starts an interactive session.

The following is the syntax of the`monkeyrunner`command:  

```
monkeyrunner -plugin <plugin_jar> <program_filename> <program_options>
```

Table 1 explains the`monkeyrunner`flags and arguments.

**Table 1.** `monkeyrunner`flags and arguments

|        Argument        |                                                                                                                                              Description                                                                                                                                               |
|------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `-plugin <plugin_jar>` | (Optional) Specifies a JAR file containing a plugin for`monkeyrunner`. To learn more about`monkeyrunner`plugins, see the[Extend monkeyrunner with plugins](https://developer.android.com/studio/test/monkeyrunner#Plugins)section. To specify more than one file, include the argument multiple times. |
| `<program_filename>`   | If you provide this argument, the`monkeyrunner`command runs the contents of the file as a Python program. Otherwise, the command starts an interactive session.                                                                                                                                        |
| `<program_options>`    | (Optional) Flags and arguments for the program in`<program_file>``. `                                                                                                                                                                                                                                  |

## monkeyrunner built-in help

You can generate an API reference for`monkeyrunner`by running:  

```
monkeyrunner help.py <format> <outfile>
```

The arguments are:

- `<format>`is either`text`for plain text output or`html`for HTML output.
- `<outfile>`is a path-qualified name for the output file.

## Extend monkeyrunner with plugins

You can extend the`monkeyrunner`API with classes you write in Java and build into one or more JAR files. You can use this feature to extend the`monkeyrunner`API with your own classes or to extend the existing classes. You can also use this feature to initialize the`monkeyrunner`environment.

To provide a plugin to`monkeyrunner`, invoke the`monkeyrunner`command with the`-plugin <plugin_jar>`argument described in[table 1](https://developer.android.com/studio/test/monkeyrunner#table1).

In your plugin code, you can import and extend the main`monkeyrunner`classes`MonkeyDevice`,`MonkeyImage`, and`MonkeyRunner`in`com.android.monkeyrunner`(see the section about[the`monkeyrunner`API](https://developer.android.com/studio/test/monkeyrunner#APIClasses)).

Note that plugins don't give you access to the Android SDK. You can't import packages such as`com.android.app`. This is because`monkeyrunner`interacts with the device or emulator below the level of the framework APIs.

### The plugin startup class

The JAR file for a plugin can specify a class that is instantiated before script processing starts. To specify this class, add the key`MonkeyRunnerStartupRunner`to the JAR file's manifest. For the value, use the name of the class to run at startup. The following snippet shows how to do this within an`ant`build script:  

```xml
<jar jarfile="myplugin" basedir="${build.dir}">
<manifest>
<attribute name="MonkeyRunnerStartupRunner" value="com.myapp.myplugin"/>
</manifest>
</jar>
```

To get access to the`monkeyrunner`tool's runtime environment, the startup class can implement`com.google.common.base.Predicate<PythonInterpreter>`. For example, this class sets up some variables in the default namespace:  

### Kotlin

```kotlin
package com.android.example

import com.google.common.base.Predicate
import org.python.util.PythonInterpreter

class Main: Predicate<PythonInterpreter> {

    override fun apply(anInterpreter: PythonInterpreter): Boolean {
        /*
         * Examples of creating and initializing variables in the monkeyrunner environment's
         * namespace. During execution, the monkeyrunner program can refer to the variables
         * "newtest" and "use_emulator"
         *
         */
        anInterpreter.set("newtest", "enabled")
        anInterpreter.set("use_emulator", 1)
        return true
    }
}
```

### Java

```java
package com.android.example;

import com.google.common.base.Predicate;
import org.python.util.PythonInterpreter;

public class Main implements Predicate<PythonInterpreter> {
    @Override
    public boolean apply(PythonInterpreter anInterpreter) {

        /*
        * Examples of creating and initializing variables in the monkeyrunner environment's
        * namespace. During execution, the monkeyrunner program can refer to the variables "newtest"
        * and "use_emulator"
        *
        */
        anInterpreter.set("newtest", "enabled");
        anInterpreter.set("use_emulator", 1);

        return true;
    }
}
```